Many individuals have heard of secondhand smoke and how harmful it can be for others. However, an offset of secondhand smoke--thirdhand smoke (THS)--is something many people do not discuss. THS consists of the remnants of secondhand smoke. Once the smoke of cigarettes/cigars has been released into the air, the chemicals within the smoke can stick to materials and surfaces around it [1]. As these THS chemicals are the same chemicals that are in secondhand smoke, they can be just as harmful for the body, especially to one's lungs. Additionally, the chemicals can also become toxins individually and/or by mixing with other chemicals within the air [2].

Thirdhand smoke can easily build up in various areas, even areas that people would least expect. These areas include, but are not limited to, carpets, walls, furniture, clothing, tables, bedding, curtains, one's hair and skin, and much more. THS residues are incredibly difficult to rid of, as they have a high resistance to normal cleaning. Hence, simply airing out the area or the materials by opening up windows, turning on the AC, or using a fan, may not make a difference. Consequently, these built up THS remnants can be harmful for people, especially babies. The chemicals within the remnants may react with each other or with other chemicals around it and potentially become carcinogenic. For instance, nicotine, one of the prime harmful ingredients of tobacco, can undergo oxidative aging with other chemicals in various environments and cause even more harm to the individuals who come in contact with its byproducts [1,2].

Thirdhand smoke is a new subject that many individuals are not aware of, but there has been some research done on the matter, especially in terms of how dangerous it can be [2]. In general, according to a 2006 Surgeon General's Report, there is no amount of tobacco smoke exposure that is safe because even a small amount can be harmful to one's health. Hence, THS should not be ignored when it comes to determining the sources of exposed tobacco smoke. Moreover, the dangers of built up THS has been proven by a study done by San Diego State University. They found that the homes of former smokers stayed contaminated by THS for up to six months, even after they had stopped smoking. A 2002 study pointed out that THS toxins, like the ones found in this SDSU study, can become re-exposed into the air and remain so even after smoking has stopped [3].

So, how can one avoid thirdhand smoke? Attempting to get rid of THS by basic cleaning, as mentioned before, may not work. Hence, the best solution is to become informed about the dangers of THS and try to keep environments smoke-free, which includes personal and public areas [2].